This disclosure relates to an additive for incorporating ultraviolet radiation (UV) protection into a polymer, and more specifically, to an additive for incorporating UV protection into a synthetic polymer with the additive and the synthetic polymer for use in manufacturing a synthetic fabric, yarn, textile or garment.
Ecological friendly fabrics or Eco-friendly fabrics are gaining in popularity and use in clothing. An Eco-friendly fabric may be a natural fiber such as cotton, hemp, or bamboo which has been grown in soil that has not been treated with pesticides for a number of years. Some examples of other Eco-friendly fabrics are organic cotton, sisal, a combination of hemp and recycled rayon, a combination of hemp and cotton, broadcloth, denim, linen, and a combination of bamboo and recycled rayon. Natural fibers, which may be derived from plants or animals, such as wool, angora, silk, alpaca, cashmere, and silk are also examples of Eco-friendly fabrics. Synthetic fabrics, which may be made from synthetic sustainable products, such as nylon, rayon, olefin, spandex, and tencel are also examples of Eco-friendly fabrics.
To assist an individual in determining whether a garment has protection against ultraviolet radiation, a rating system has been developed. This rating system is known in the industry as the UPF (Ultraviolet Protection Factor) rating system. Clothing having a rating of UPF 50 are able to block out 98% of the sun's ultraviolet radiation. Further, by way of example, a garment having a rating of UPF 15-24 will only block out 93.3% to 95.9% of ultraviolet radiation. Exposure to the sun's harmful ultraviolet radiation (known as UVA/UVB rays) can damage the skin, can cause sunburn, and can lead to skin cancer over prolonged exposure.
There are a number of factors that affect the level of ultraviolet radiation protection provided by a fabric and the UPF rating. Some factors are the weave of the fabric, the color of the fabric, the weight of the fabric, the fiber composition of the fabric, the stretch of the fabric, moisture content of the fabric. If the fabric has a tight weave or a high thread count then the fabric will have a higher UPF rating. However, even though the fabric has a higher UPF rating, the fabric may be less comfortable because a tighter weave or higher thread count means that the fabric is heavy or uncomfortable to wear. Another factor that affects protection is the addition of chemicals such as UV absorbers or UV diffusers during the manufacturing process. As can be appreciated, some of the features that make a garment comfortable to wear also make the garment less protective. A challenge for a clothing manufacturer is to provide clothing having both protection from the sun and being comfortable to wear.
Athletic clothing or active wear clothing is typically manufactured from synthetic material such as polyester or nylon. Polyester may be formed into a filament yarn that is used to weave a fabric or garment. To form polyester, dimethyl terephthalate is placed in a container and first reacted with ethylene glycol in the presence of a catalyst at a temperature of 302-410° F. The resulting chemical, a monomer alcohol, is combined with terephthalic acid and raised to a temperature of 472° F. Newly-formed polyester, which is clear and molten, is extruded through a slot provided in the container to form long ribbons. the long molten ribbons are allowed to cool until they become brittle. The ribbons are cooled and then cut into tiny polymer chips. These tiny polymer chips are then melted at 500-518° F. to form a syrup-like melt or liquid. This melt is put into a metal container called a spinneret and forced through its tiny holes to produce special fibers. The emerging fibers are brought together to form a single strand. This strand is wound on a bobbin for further processing or to be woven into yarn.
Therefore, it would be desirable to provide an additive for incorporating ultraviolet radiation protection into a polymer prior to a polymer yarn being fabricated. Moreover, there is a need for a process for incorporating UV protection into a polymer so that the polymer may be further processed into a yarn that may be used to manufacture a fabric so that the fabric may be used to protect an individual from UV radiation. Furthermore, it would be advantageous to incorporate adequate protection in a garment, fabric, or textile to protect against exposure to UV radiation, to increase the UV resistance of a garment, fabric, or textile, or to enhance UV radiation absorption of a garment, fabric, or textile to protect an individual from UV radiation.